iral and it uses the
utmost finish in the whirling process. The Epeira, to spread her net,
has but an hour's sitting at the most, wherefore the speed at which she
works compels her to rest content with a simpler production. She
shortens the task by confining herself to a skeleton of the curve which
the other describes to perfection.

The Epeira, therefore, is versed in the geometric secrets of the Ammonite
and the _Nautilus pompilus_; she uses, in a simpler form, the logarithmic
line dear to the Snail. What guides her? There is no appeal here to a
wriggle of some kind, as in the case of the Worm that ambitiously aspires
to become a Mollusc. The animal must needs carry within itself a virtual
diagram of its spiral. Accident, however fruitful in surprises we may
presume it to be, can never have taught it the higher geometry wherein
our own intelligence at once goes astray, without a strict preliminary
training.

Are we to recognize a mere effect of organic structure in the Epeira's
art? We readily think of the legs, which, endowed with a very varying
power of extension, might serve as compasses. More or less bent, more or
less outstretched, they would mechanically determine the angle whereat
the spiral shall intersect the radius; they would maintain the parallel
of the chords in each sector.

Certain objections arise to affirm that, in this instance, the tool is
not the sole regulator of the work. Were the arrangement of the thread
determined by the length of the legs, we should find the spiral volutes
separated more widely from one another in proportion to the greater
length of implement in the spinstress. We see this in the Banded Epeira
and the Silky Epeira. The first has longer limbs and spaces her cross-
threads more liberally than does the second, whose legs are shorter.

But we must not rely too much on this rule, say others. The Angular
Epeira, the Paletinted Epeira and the Cross Spider, all three more or
less short-limbed, rival the Banded Epeira in the spacing of their lime-
snares. The last two even dispose them with greater intervening
distances.

We recognize in another respect that the organization of the animal does
not imply an immutable type of work. Before beginning the sticky spiral,
the Epeirae first spin an auxiliary intended to strengthen the stays.
This spiral, formed of plain, non-glutinous thread, starts from the
centre and winds in rapidly-widening circles to the circumference.